US11728873B2

US11728873B2 - Early beam failure detection

Info

Publication number: US11728873B2
Application number: US17/372,334
Authority: US
Inventors: Shanyu Zhou; Jelena Damnjanovic; Tao Luo
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2021-07-09
Filing date: 2021-07-09
Publication date: 2023-08-15
Also published as: CN117597871A; US20230013751A1; KR20240007317A; WO2023283019A1

Abstract

A method of wireless communication may include a UE and a base station. The base station may transmit at least one BFD-RS to the UE and the UE may receive at least one BFD-RS from a base station. The UE may transmit an aperiodic BFI report to the base station prior to a beam failure detection. The base station may determine that an early beam failure occurred and initiate a beam failure recovery in response to receiving the aperiodic BFI report from the UE.

Description

TECHNICAL FIELD

The present disclosure relates generally to communication systems, and more particularly, to a method of wireless communication including an early beam failure detection.

INTRODUCTION

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

BRIEF SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may include a base station and a UE. The base station may transmit at least one beam failure detection (BFD) reference signal (RS) (BFD-RS) to the UE and the UE may receive at least one BFD-RS from a base station. The UE may determine BFI counts based on the measurement of the BFD-RS, and transmit the aperiodic BFI report to the base station prior to detecting the beam failure. The UE may transmit an aperiodic beam failure indication (BFI) report to the base station prior to the beam failure detection. The base station may receive the aperiodic BFI report and determine whether an early beam failure occurred based on the received aperiodic BFI Report. The base station may initiate the beam failure recovery.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIG. 2A is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure.

FIG. 2B is a diagram illustrating an example of DL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 2C is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure.

FIG. 2D is a diagram illustrating an example of UL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4 is a communication diagram of a method of wireless communication.

FIG. 5 is a communication diagram of a method of wireless communication including an early beam failure detection.

FIG. 6 is a flowchart of a method of wireless communication.

FIG. 7 is a flowchart of a method of wireless communication.

FIG. 8 is a flowchart of a method of wireless communication.

FIG. 9 is a flowchart of a method of wireless communication.

FIG. 10 is a diagram illustrating an example of a hardware implementation for an example apparatus.

FIG. 11 is a diagram illustrating an example of a hardware implementation for an example apparatus.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC)). The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface). The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network 190 through second backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over third backhaul links 134 (e.g., X2 interface). The first backhaul links 132, the second backhaul links 184, and the third backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102/UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell).

Certain UEs

104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs 152/AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP 150. The small cell 102′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz). Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz-71 GHz), FR4 (52.6 GHz-114.25 GHz), and FR5 (114.25 GHz-300 GHz). Each of these higher frequency bands falls within the EHF band.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band.

A base station 102, whether a small cell 102′ or a large cell (e.g., macro base station), may include and/or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182′. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182″. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180/UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180/UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include an Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services.

The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit reception point (TRP), or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and/or individually access the network.

Referring again to FIG. 1 , in certain aspects, the UE 104 may include an early beam failure reporting component 198 configured to receive, from a base station, at least one BFD-RS, and transmit, to the base station, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station. In certain aspects, the base station 180 may include an early beam failure reporting component 199 configured to transmit, from a UE, at least one BFD-RS, and receive, from the UE, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth), subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGS. 2A, 2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL), where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 1 (with all UL). While

subframes

3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI), or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI). Note that the description infra applies also to a 5G NR frame structure that is TDD.

FIGS. 2A-2D illustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission). The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) and, effectively, the symbol length/duration, which is equal to 1/SCS.


μ	SCS Δf = 2^μ · 15 [kHz]	Cyclic prefix

0	15	Normal
1	30	Normal
2	60	Normal, Extended
3	120	Normal
4	240	Normal

For normal CP (14 symbols/slot), different numerologies μ0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols/slot and 2^μ slots/subframe. The subcarrier spacing may be equal to 2^μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGS. 2A-2D provide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended).

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS).

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET). A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH), which carries a master information block (MIB), may be logically grouped with the PSS and SSS to form a synchronization signal (SS)/PBCH block (also referred to as SS block (SSB)). The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS). The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and/or negative ACK (NACK)). The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375

implements layer

3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318 TX. Each transmitter 318 TX may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354 RX receives a signal through its respective antenna 352. Each receiver 354 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1 . At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects in connection with 199 of FIG. 1 .

FIG. 4 is a communication diagram 400 of a method of wireless communication. The communication diagram 400 may include a UE 402 and a base station 404. The UE 402 and the base station 404 may communicate using a beam-formed signal. The communication diagram 400 may illustrate a beam failure detection process.

At 406, the base station 404 may send a BFD-RS to the UE 402 for measurement. The base station 404 may send the BFD-RS to the UE 402, and the UE 402 may measure the BFD-RS to detect the radio link quality between the base station 404 and the UE 402. The UE 402 may detect the beam failure based on the detected radio link quality between the UE 402 and the base station 404. In one aspect, the BFD-RS may be transmitted periodically, and the UE 402 may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include channel status information (CSI) reference signal (RS) (CSI-RS), a synchronization signal block (SSB), or reference signal comprised in the SSB.

At 408, the UE 402 may measure the BFD-RS received from the base station 404 to detect the radio link quality. In one aspect, the UE 402 may measure a signal to noise and interference ratio (SINR) of the BFD-RS and estimate a block error rate (BLER) of the received BFD-RS. The aspects of the disclosure are not limited thereto, and the measurement of the BFD-RS may include a signal-to-noise ratio (SNR), a reference signal received power (RSRP), a path-loss measurement, etc.

At 410, the UE 402 may determine BFI counts based on the measurement of the BFD-RS at 408. First, the UE 402 may compare the estimated BLER to a BLER threshold value (e.g., which may be referred to as a “threshold_bler”). In one aspect, the estimated BLER may be less than or equal to the BLER threshold value (e.g., BLER≤threshold_bler), and the UE 402 may determine that beam failure did not occur. In another aspect, the estimated BLER may be greater than the BLER threshold value (e.g., BLER>threshold_bler), and the UE 402 may detect that the radio link quality is below the threshold value. In response to the estimated BLER being greater than the BLER threshold value (e.g., BLER>threshold_bler), the physical layer of the UE 402 may record the BFI to the MAC layer of the UE 402.

In response to the first BFI being reported from the physical layer to the MAC layer, the MAC layer may start a BFD timer. The MAC layer of the UE 402 may increase the BFI counts by 1 for each BFI being reported from the lower layer, e.g., the physical layer. The MAC layer of the UE 402 may maintain the BFI counts while the BFD timer runs. The BFD timer may expire, and the MAC layer of the UE 402 may reset the BFI counts.

At 412, the UE 402 may compare the BFI counts with a threshold value (e.g., a maxCount threshold value) to declare the beam failure. That is, the MAC layer of the UE 402 may compare the total BFI counts with the threshold value. The UE 402 may determine that the beam failure occurred in response to the BFI counts being greater than or equal to the threshold value.

At 414, the UE 402 may declare the beam failure in response to the total BFI counts within a period of time reaching the threshold value, e.g., with the period of time being before the BFD timer expires. That is, in response to the BFI counts being greater than or equal to the threshold value within a period of time, the MAC layer of the UE 402 may declare the beam failure. The UE 402 may reset the BFI counts in response to the expiration of the BFD timer, and the UE 402 may declare the beam failure if the total BFI counts reach the threshold value before the BFD timer expires.

At 416, the UE 402 may initiate the beam failure recovery (BFR) procedure in response to declaring the beam failure. That is, if the MAC layer of the UE 402 declares the beam failure, the UE 402 may enter the BFR procedure. The UE 402 may initiate the BFR procedure by initiating the RACH procedure with the base station 404 or otherwise indicating the BFD to the base station.

At 418, the UE 402 may transmit the random access request to the base station 404. That is, the UE 402 may initiate the RACH procedure to initiate the BFR procedure with the base station 404.

Based on the communication diagram 400 of a method of wireless communication, the UE 402 may declare the beam failure after the BFI counts reach the threshold number of counts, (e.g., which may be referred to as a maxCount threshold value), and the UE 402 may spend increased time and resources in the recovery of the failed beams. Also, it may not be efficient for the UE 402 to communicate the channel condition to base station 404 for the purpose of declaring beam failure because it may increase the delay and power consumption at the UE 402.

From the base station 404 side, there may be no reporting during the process of BFD, and the base station 404 is unaware of the UE's BFD status in a timely manner. That is, the base station 404 may understand the beam failure condition at the UE 402 in response to the UE 402 initiating the RACH procedure for the BFR procedure. That is, the beam failure at the UE 402 may be transparent to the base station 404 until the base station 404 received the random access request from the UE 402 initiated for the BFR procedure. Accordingly, the BFR may be time and power-consuming and may have increased latency in response to the occurrence of the beam failure.

In some aspects, aperiodic BFI reporting may be provided for the early detection of beam failure. In one aspect, the aperiodic BFI reporting may provide faster beam failure recovery procedures, e.g., beam switching, instead of the BFR procedure including the RACH procedure. In another aspect, the aperiodic BFI reporting may have reduced power consumption compared to the BFR procedure including the RACH procedure. In another aspect, the base station 404 may receive a more comprehensive channel condition record and take the comprehensive channel condition record into consideration to determine the early detection of the beam failure. In another aspect, the base station 404 may have a global understanding of the serving UEs.

FIG. 5 is a communication diagram 500 of a method of wireless communication including an early beam failure detection. The communication diagram 500 may include a UE 502 and a base station 504. The UE 502 and the base station 504 may communicate using a beam-formed signal. The communication diagram 500 may illustrate an early beam failure detection process.

At 506, the base station 504 may transmit, to the UE 502, at least one BFD-RS for measurement, and the UE 502 may receive, from the base station 504, at least one BFD-RS. The base station 504 may send the BFD-RS to the UE 502, and the UE 502 may measure the BFD-RS to detect the radio link quality between the base station 504 and the UE 502. In one aspect, the BFD-RS may be transmitted periodically, and the UE 502 may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include the CSI-RS, the SSB, or a signal comprised in the SSB.

At 508, the base station 504 may transmit, to the UE 502, a configuration of the aperiodic BFI report, the aperiodic BFI report being generated based on the configuration received from the base station 504. The UE 502 may receive, from the base station 504, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station 504. The configuration of the aperiodic BFI report may include a triggering condition for the UE 502 to transmit the aperiodic BFI report in response to meeting the triggering condition. The configuration of the aperiodic BFI report may also indicate the content of the aperiodic BFI report.

In one aspect, the configuration of the aperiodic BFI report may be received via at least one of an RRC message configuring a plurality of parameters of the aperiodic BFI report, or a MAC-CE or DCI activating at least one parameter of the aperiodic BFI report among the of parameters of the aperiodic BFI report configured by the RRC message.

At 510, the base station 504 may transmit, to the UE 502, an instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is received from the UE 502 in response to transmitting the instruction to the UE 502. The UE 502 may receive, from the base station 504, the instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is transmitted to the base station 504 in response to receiving the instruction from the base station 504. The instruction to transmit the aperiodic BFI report may indicate the UE 502 to enter the aperiodic BFI reporting status. The instruction to transmit the aperiodic BFI report may be transmitted via a MAC-CE or DCI.

In some aspects, the instruction triggering the aperiodic BFI report may be transmitted based on an occurrence of a condition at the base station 504. In one aspect, the base station 504 may transmit the instruction triggering the aperiodic BFI report based on a sudden channel condition change detected among served UEs. That is, the base station 504 may determine that the channel status of the one or more UEs served by the base station 504 and transmit the instruction triggering the aperiodic BFI report to the UE 502. For example, the at least one BFI count at the UE 502 may be equal to a threshold BFI value, the first number of BFIs are consecutively reported at the UE 502, the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE 502, or based on at least one channel condition measurement associated with the UE 502. In another aspect, the base station 504 may determine to have an update of current serving UE 502's BFD state. For example, the base station 504 may be configured to perform a conditional handover, and the base station 504 may instruct all serving UEs to update the BFD status of all the serving UEs.

At 512, the UE 502 may measure the BFD-RS received from the base station 504 to detect the radio link quality. In one aspect, the UE 502 may measure the SINR of the BFD-RS and estimate the BLER of the received BFD-RS. The aspects of the disclosure are not limited to measuring the SINR and the BLER, and the measurement of the BFD-RS may include an SNR, an RSRP, a path-loss measurement, etc.

At 514, the UE 502 may determine BFI counts based on the measurement of the BFD-RS at 512. First, the UE 502 may compare the estimated BLER to a BLER threshold value (e.g., which may be referred to as a “threshold_bler”). In one aspect, the estimated BLER may be less than or equal to the BLER threshold value (e.g., BLER≤threshold_bler), and the UE 502 may determine that beam failure did not occur. In another aspect, the estimated BLER may be greater than the BLER threshold value (e.g., BLER>threshold_bler), and the UE 502 may detect that the radio link quality is below the threshold value. In response to the estimated BLER being greater than the BLER threshold value (e.g., BLER>threshold_bler), the physical layer of the UE 502 may record the BFI to the MAC layer of the UE 502. The aspects of the disclosure are not limited to measuring the SINR and the BLER, and the measurement of the BFD-RS may include an SNR, an RSRP, a path-loss measurement, etc.

At 516, the UE 502 may transmit, to the base station 504, an aperiodic beam failure indication (BFI) report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station 504. The base station 504 may receive, from the UE 502, the aperiodic BFI report prior to the beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE 502. The UE 502 may determine to enter the aperiodic BFI reporting status and transmit the aperiodic BFI report. The aperiodic BFI report may be transmitted via a MAC-CE or UCI.

In some aspects, the aperiodic BFI report may provide a BFD status update to the base station 504. In one aspect, the aperiodic BFI report may include the BFI counts within a period of time from the 514, the BFI being reported in response to a comparison of at least one measurement of the BFD-RS to a threshold value. That is, the UE 502 may report the BFI counts to the base station 504 using the aperiodic BFI report. In another aspect, the aperiodic BFI report may include one or more channel condition measurements of the BFD-RS. That is, the UE 502 may report one or more channel condition measurements, such as SINR, RSPR, etc., using the aperiodic BFI report. In another aspect, the aperiodic BFI report may be transmitted with a CSI report. That is, the UE 502 may include the CSI report in the aperiodic BFI report as the status update for the base station 504. In one aspect, the configuration of the aperiodic BFI report received at 508 may configure the content of the aperiodic BFI report. In another aspect, a specification at the UE 502 may configure the content of the aperiodic BFI report.

The aperiodic BFI report may be transmitted to the base station 504 in response to the triggering condition based on the BFI counts. The UE 502 may be configured by the base station 504 with multiple BFI reporting events. The BFI reporting events may be configured by the configuration of the aperiodic BFI report received at 508. The UE 502 may be configured to report the aperiodic BFI report when at least one of the above events is satisfied.

In one aspect, the triggering condition may include the BFI counts being equal to a threshold BFI value. That is, the UE 502 may be triggered to transmit the aperiodic BFI report to the base station 504 in response to the BFI counts approaching a maxCount threshold. In another aspect, the triggering condition may include a first number of BFIs being consecutively reported. That is, the UE 502 may be triggered to transmit the aperiodic BFI report to the base station 504 in response to N consecutive number of BFIs being recorded. In another aspect, the triggering condition may include the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS. That is, the UE 502 may be triggered to transmit the aperiodic BFI report to the base station 504 in response to a sudden change of channel condition being detected. For example, the UE 502 may transmit the aperiodic BFI report to the base station 504 in response to the SINR dropping more than X dB from the previous measurement.

At 518, the base station 504 may determine whether an early beam failure occurred based on the received aperiodic BFI report. The base station 504 may detect the early beam failure based on predefined early BFD indicating events. That is, the base station 504 may determine that the early beam failure occurred based on the occurrence of one or more early BFD indicating events or conditions. In one aspect, the base station 504 may determine that the early beam failure occurred base on at least one BFI count at the UE 502 being equal to a threshold BFI value. In another aspect, the base station 504 may determine that the early beam failure occurred base on a first number of BFIs being consecutively reported at the UE 502. In another aspect, the base station 504 may determine that the early beam failure occurred base on the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE 502. In another aspect, the base station 504 may determine that the early beam failure occurred base on at least one channel condition measurement associated with the UE 502.

At 520, the base station 504 may initiate a beam failure recovery, the beam failure recovery including at least one of initiating a beam switch of the UE 502, silencing other UEs neighboring the UE 502, initiate conditional hand over to a nearby base station. In one aspect, the base station 504 may initiate a beam failure recovery by initiating a beam switch procedure. That is, the base station 504 may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE 502, initiate beam switching and instruct the UE 502 to switch beam. In another aspect, the base station 504 may initiate a beam failure recovery by silencing certain UE 502 to expedite data transmission for high-priority UEs. That is, the base station 504 may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE 502, instruct one or more UEs that may be causing noise signal to the UE 502 to stop the wireless communication and prioritize the data transmission with the UE 502. In another aspect, the base station 504 may initiate a beam failure recovery by initiating a conditional handover request to nearby base stations. That is, the base station 504 may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE 502, initiate a handover procedure with the nearby base station to hand over the wireless communication with the UE 502 to the nearby base station that may provide better wireless connection.

FIG. 6 is a flowchart 600 of a method of wireless communication. The method may be performed by a UE (e.g., the UE 104; the apparatus 1002). The UE may receive at least one BFD-RS from the base station and transmit an aperiodic BFI report to the base station prior to a beam failure detection.

At 602, the UE may receive, from the base station, at least one BFD-RS. The base station may send the BFD-RS to the UE, and the UE may measure the BFD-RS to detect the radio link quality between the base station and the UE. In one aspect, the BFD-RS may be transmitted periodically, and the UE may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include the CSI-RS, the SSB, or a signal comprised in the SSB. For example, at 506, the UE 502 may receive, from the base station 504, at least one BFD-RS. Also, 602 may be performed by a BFD-RS component 1040.

At 604, the UE may receive, from the base station, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station. The configuration of the aperiodic BFI report may include a triggering condition for the UE to transmit the aperiodic BFI report in response to meeting the triggering condition. The configuration of the aperiodic BFI report may also indicate the content of the aperiodic BFI report. In one aspect, the configuration of the aperiodic BFI report may be received via at least one of an RRC message configuring a plurality of parameters of the aperiodic BFI report, or a MAC-CE or DCI activating at least one parameter of the aperiodic BFI report among the of parameters of the aperiodic BFI report configured by the RRC message. For example, at 508, the UE 502 may receive, from the base station 504, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station 504. Also, 604 may be performed by a BFI report component 1042.

At 606, the UE may receive, from the base station, the instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is transmitted to the base station in response to receiving the instruction from the base station. The instruction to transmit the aperiodic BFI report may indicate the UE to enter the aperiodic BFI reporting status. The instruction to transmit the aperiodic BFI report may be transmitted via a MAC-CE or DCI. In some aspects, the instruction triggering the aperiodic BFI report may be transmitted based on an occurrence of a condition at the base station. In one aspect, the base station may transmit the instruction triggering the aperiodic BFI report based on a sudden channel condition change detected among served UEs. That is, the base station may determine that the channel status of the one or more UEs served by the base station and transmit the instruction triggering the aperiodic BFI report to the UE. For example, the at least one BFI count at the UE may be equal to a threshold BFI value, the first number of BFIs are consecutively reported at the UE, the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE, or based on at least one channel condition measurement associated with the UE. In another aspect, the base station may determine to have an update of current serving UE's BFD state. For example, the base station may be configured to perform a conditional handover, and the base station may instruct all serving UEs to update the BFD status of all the serving UEs. For example, at 510, the UE 502 may receive, from the base station 504, the instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is transmitted to the base station 504 in response to receiving the instruction from the base station 504. Also, 606 may be performed by the BFI report component 1042.

At 608, the UE may measure the BFD-RS received from the base station to detect the radio link quality. In one aspect, the UE may measure the SINR of the BFD-RS and estimate the BLER of the received BFD-RS. The aspects of the disclosure are not limited to measuring the SINR and the BLER, and the measurement of the BFD-RS may include an SNR, an RSRP, a path-loss measurement, etc. For example, at 512, the UE 502 may measure the BFD-RS received from the base station 504 to detect the radio link quality. Also, 608 may be performed by the BFD-RS component 1040.

At 610, the UE may determine the BFI counts based on the measurement of the BFD-RS at 604. First, the UE may compare the estimated BLER to a BLER threshold value (e.g., which may be referred to as a “threshold_bler”). In one aspect, the estimated BLER may be less than or equal to the BLER threshold value (e.g., BLER≤threshold_bler), and the UE may determine that beam failure did not occur. In another aspect, the estimated BLER may be greater than the BLER threshold value (e.g., BLER>threshold_bler), and the UE may detect that the radio link quality is below the threshold value. In response to the estimated BLER being greater than the BLER threshold value (e.g., BLER>threshold_bler), the physical layer of the UE may record the BFI to the MAC layer of the UE. The aspects of the disclosure are not limited to measuring the SINR and the BLER, and the measurement of the BFD-RS may include an SNR, an RSRP, a path-loss measurement, etc. For example, at 514, the UE 502 may determine BFI counts based on the measurement of the BFD-RS at 508. Also, 610 may be performed by the BFI report component 1042.

At 612, the UE may transmit, to the base station, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station. The UE may determine to enter the aperiodic BFI reporting status and transmit the aperiodic BFI report report. The aperiodic BFI report may be transmitted via a MAC-CE or UCI. For example, at 516, the UE 502 may transmit, to the base station 504, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station 504. Also, 612 may be performed by the BFI report component 1042.

In some aspects, the aperiodic BFI report may provide a BFD status update to the base station. In one aspect, the aperiodic BFI report may include the BFI counts within a period of time from the 514, the BFI being reported in response to a comparison of at least one measurement of the BFD-RS to a threshold value. That is, the UE may report the BFI counts to the base station using the aperiodic BFI report. In another aspect, the aperiodic BFI report may include one or more channel condition measurements of the BFD-RS. That is, the UE may report one or more channel condition measurements, such as SINR, RSPR, etc., using the aperiodic BFI report. In another aspect, the aperiodic BFI report may be transmitted with a CSI report. That is, the UE may include the CSI report in the aperiodic BFI report as the status update for the base station. In one aspect, the configuration of the aperiodic BFI report received at 604 may configure the content of the aperiodic BFI report. In another aspect, a specification at the UE may configure the content of the aperiodic BFI report.

The aperiodic BFI report may be transmitted to the base station in response to the triggering condition based on the BFI counts. The UE may be configured by the base station with multiple BFI reporting events. The BFI reporting events may be configured by the configuration of the aperiodic BFI report received at 604. The UE may be configured to report the aperiodic BFI report when at least one of the above events is satisfied.

In one aspect, the triggering condition may include the BFI counts being equal to a threshold BFI value. That is, the UE may be triggered to transmit the aperiodic BFI report to the base station in response to the BFI counts approaching a maxCount threshold. In another aspect, the triggering condition may include a first number of BFIs being consecutively reported. That is, the UE may be triggered to transmit the aperiodic BFI report to the base station in response to N consecutive number of BFIs being recorded. In another aspect, the triggering condition may include the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS. That is, the UE may be triggered to transmit the aperiodic BFI report to the base station in response to a sudden change of channel condition being detected. For example, the UE may transmit the aperiodic BFI report to the base station in response to the SINR dropping more than X dB from the previous measurement.

FIG. 7 is a flowchart 700 of a method of wireless communication. The method may be performed by a UE (e.g., the UE 104; the apparatus 1002). The UE may receive at least one BFD-RS from the base station and transmit an aperiodic BFI report to the base station prior to a beam failure detection.

At 702, the UE may receive, from the base station, at least one BFD-RS. The base station may send the BFD-RS to the UE, and the UE may measure the BFD-RS to detect the radio link quality between the base station and the UE. In one aspect, the BFD-RS may be transmitted periodically, and the UE may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include the CSI-RS, the SSB, or a signal comprised in the SSB. For example, at 506, the UE 502 may receive, from the base station 504, at least one BFD-RS. Also, 702 may be performed by a BFD-RS component 1040.

At 712, the UE may transmit, to the base station, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station. The UE may determine to enter the aperiodic BFI reporting status and transmit the aperiodic BFI report. The aperiodic BFI report may be transmitted via a MAC-CE or UCI. For example, at 516, the UE 502 may transmit, to the base station 504, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station 504. Also, 712 may be performed by the BFI report component 1042.

In some aspects, the aperiodic BFI report may provide a BFD status update to the base station. In one aspect, the aperiodic BFI report may include the BFI counts within a period of time from the 514, the BFI being reported in response to a comparison of at least one measurement of the BFD-RS to a threshold value. That is, the UE may report the BFI counts to the base station using the aperiodic BFI report. In another aspect, the aperiodic BFI report may include one or more channel condition measurements of the BFD-RS. That is, the UE may report one or more channel condition measurements, such as SINR, RSPR, etc., using the aperiodic BFI report. In another aspect, the aperiodic BFI report may be transmitted with a CSI report. That is, the UE may include the CSI report in the aperiodic BFI report as the status update for the base station. In one aspect, the received configuration of the aperiodic BFI report may configure the content of the aperiodic BFI report. In another aspect, a specification at the UE may configure the content of the aperiodic BFI report.

The aperiodic BFI report may be transmitted to the base station in response to the triggering condition based on the BFI counts. The UE may be configured by the base station with multiple BFI reporting events. The BFI reporting events may be configured by the received configuration of the aperiodic BFI report. The UE may be configured to report the aperiodic BFI report when at least one of the above events is satisfied.

FIG. 8 is a flowchart 800 of a method of wireless communication. The method may be performed by a base station (e.g., the base station 102/180; the apparatus 1102). The base station may transmit at least one BFD-RS to the UE and receive an aperiodic BFI report from the UE prior to a beam failure detection. The base station may determine that an early beam failure occurred and initiate a beam failure recovery in response to receiving the aperiodic BFI report from the UE.

At 802, the base station may transmit, to the UE, at least one BFD-RS for measurement. The base station may send the BFD-RS to the UE, and the UE may measure the BFD-RS to detect the radio link quality between the base station and the UE. In one aspect, the BFD-RS may be transmitted periodically, and the UE may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include the CSI-RS, the SSB, or a signal comprised in the SSB. For example, at 506, the base station 504 may transmit, to the UE 502, at least one BFD-RS for measurement. Also, 802 may be performed by a BFD-RS component 1140.

At 804, the base station may transmit, to the UE, a configuration of the aperiodic BFI report, the aperiodic BFI report being generated based on the configuration received from the base station. The configuration of the aperiodic BFI report may include a triggering condition for the UE to transmit the aperiodic BFI report in response to meeting the triggering condition. The configuration of the aperiodic BFI report may also indicate the content of the aperiodic BFI report. In one aspect, the configuration of the aperiodic BFI report may be received via at least one of an RRC message configuring a plurality of parameters of the aperiodic BFI report, or a MAC-CE or DCI activating at least one parameter of the aperiodic BFI report among the of parameters of the aperiodic BFI report configured by the RRC message. For example, at 508, the base station 504 may transmit, to the UE 502, a configuration of the aperiodic BFI report, the aperiodic BFI report being generated based on the configuration received from the base station 504. Also, 804 may be performed by the BFD-RS component 1140.

At 806, the base station may transmit, to the UE, an instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is received from the UE in response to transmitting the instruction to the UE. The instruction to transmit the aperiodic BFI report may indicate the UE to enter the aperiodic BFI reporting status. The instruction to transmit the aperiodic BFI report may be transmitted via a MAC-CE or DCI. In some aspects, the instruction triggering the aperiodic BFI report may be transmitted based on an occurrence of a condition at the base station. In one aspect, the base station may transmit the instruction triggering the aperiodic BFI report based on a sudden channel condition change detected among served UEs. That is, the base station may determine that the channel status of the one or more UEs served by the base station and transmit the instruction triggering the aperiodic BFI report to the UE. For example, the at least one BFI count at the UE may be equal to a threshold BFI value, the first number of BFIs are consecutively reported at the UE, the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE, or based on at least one channel condition measurement associated with the UE. In another aspect, the base station may determine to have an update of current serving UE's BFD state. For example, the base station may be configured to perform a conditional handover, and the base station may instruct all serving UEs to update the BFD status of all the serving UEs. For example, at 510, the base station 504 may transmit, to the UE 502, an instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is received from the UE 502 in response to transmitting the instruction to the UE 502. Also, 806 may be performed by the BFD-RS component 1140.

At 808, the base station may receive, from the UE, the aperiodic BFI report prior to the beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE. The UE may determine to enter the aperiodic BFI reporting status and transmit the aperiodic BFI report. The aperiodic BFI report may be transmitted via a MAC-CE or UCI. For example, at 516, the base station 504 may receive, from the UE 502, the aperiodic BFI report prior to the beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE 502. Also, 808 may be performed by the BFD-RS component 1140.

In some aspects, the aperiodic BFI report may provide a BFD status update to the base station. In one aspect, the aperiodic BFI report may include the BFI counts within a period of time at the UE, the BFI being reported in response to a comparison of at least one measurement of the BFD-RS to a threshold value. That is, the UE may report the BFI counts to the base station using the aperiodic BFI report. In another aspect, the aperiodic BFI report may include one or more channel condition measurements of the BFD-RS. That is, the UE may report one or more channel condition measurements, such as SINR, RSPR, etc., using the aperiodic BFI report. In another aspect, the aperiodic BFI report may be transmitted with a CSI report. That is, the UE may include the CSI report in the aperiodic BFI report as the status update for the base station. In one aspect, the configuration of the aperiodic BFI report transmitted at 804 may configure the content of the aperiodic BFI report. In another aspect, a specification at the UE may configure the content of the aperiodic BFI report.

The aperiodic BFI report may be transmitted to the base station in response to the triggering condition based on the BFI counts. The UE may be configured by the base station with multiple BFI reporting events. The BFI reporting events may be configured by the configuration of the aperiodic BFI report transmitted at 804. The UE may be configured to report the aperiodic BFI report when at least one of the above events is satisfied.

At 810, the base station may determine whether an early beam failure occurred based on the received aperiodic BFI report. The base station may detect the early beam failure based on predefined early BFD indicating events. That is, the base station may determine that the early beam failure occurred based on the occurrence of one or more early BFD indicating events or conditions. In one aspect, the base station may determine that the early beam failure occurred base on at least one BFI count at the UE being equal to a threshold BFI value. In another aspect, the base station may determine that the early beam failure occurred base on a first number of BFIs being consecutively reported at the UE. In another aspect, the base station may determine that the early beam failure occurred base on the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE. In another aspect, the base station may determine that the early beam failure occurred base on at least one channel condition measurement associated with the UE. For example, at 518, the base station 504 may determine whether an early beam failure occurred based on the received aperiodic BFI report. Also, 810 may be performed by an early beam failure component 1144.

At 812, the base station may initiate a beam failure recovery, the beam failure recovery. The beam failure recovery may include at least one of initiating a beam switch of the UE, silencing other UEs neighboring the UE, initiate conditional hand over to a nearby base station. In one aspect, the base station may initiate a beam failure recovery by initiating a beam switch procedure. That is, the base station may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE, initiate beam switching and instruct the UE to switch beam. In another aspect, the base station may initiate a beam failure recovery by silencing certain UE to expedite data transmission for high-priority UEs. That is, the base station may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE, instruct one or more UEs that may be causing noise signal to the UE to stop the wireless communication and prioritize the data transmission with the UE. In another aspect, the base station may initiate a beam failure recovery by initiating a conditional handover request to nearby base stations. That is, the base station may, upon detecting the early beam failure based on the aperiodic BFI report received from the UE, initiate a handover procedure with the nearby base station to hand over the wireless communication with the UE to the nearby base station that may provide better wireless connection. For example, at 520, the base station 504 may initiate a beam failure recovery, the beam failure recovery. Also, 812 may be performed by a beam failure recovery component 1146.

FIG. 9 is a flowchart 900 of a method of wireless communication. The method may be performed by a base station (e.g., the base station 102/180; the apparatus 1102). The base station may transmit at least one BFD-RS to the UE and receive an aperiodic BFI report from the UE prior to a beam failure detection. The base station may initiate a beam failure recovery in response to receiving the aperiodic BFI report from the UE.

At 902, the base station may transmit, to the UE, at least one BFD-RS for measurement. The base station may send the BFD-RS to the UE, and the UE may measure the BFD-RS to detect the radio link quality between the base station and the UE. In one aspect, the BFD-RS may be transmitted periodically, and the UE may periodically measure the BFD-RS to detect the beam failure. In another aspect, the BFD-RS may include the CSI-RS, the SSB, or a signal comprised in the SSB. For example, at 506, the base station 504 may transmit, to the UE 502, at least one BFD-RS for measurement. Also, 902 may be performed by a BFD-RS component 1140.

At 908, the base station may receive, from the UE, the aperiodic BFI report prior to the beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE. The UE may determine to enter the aperiodic BFI reporting status and transmit the aperiodic BFI report. The aperiodic BFI report may be transmitted via a MAC-CE or UCI. For example, at 516, the base station 504 may receive, from the UE 502, the aperiodic BFI report prior to the beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE 502. Also, 908 may be performed by the BFD-RS component 1140.

In some aspects, the aperiodic BFI report may provide a BFD status update to the base station. In one aspect, the aperiodic BFI report may include the BFI counts within a period of time at the UE, the BFI being reported in response to a comparison of at least one measurement of the BFD-RS to a threshold value. That is, the UE may report the BFI counts to the base station using the aperiodic BFI report. In another aspect, the aperiodic BFI report may include one or more channel condition measurements of the BFD-RS. That is, the UE may report one or more channel condition measurements, such as SINR, RSPR, etc., using the aperiodic BFI report. In another aspect, the aperiodic BFI report may be transmitted with a CSI report. That is, the UE may include the CSI report in the aperiodic BFI report as the status update for the base station. In one aspect, the transmitted configuration of the aperiodic BFI report may configure the content of the aperiodic BFI report. In another aspect, a specification at the UE may configure the content of the aperiodic BFI report.

The aperiodic BFI report may be transmitted to the base station in response to the triggering condition based on the BFI counts. The UE may be configured by the base station with multiple BFI reporting events. The BFI reporting events may be configured by the configuration of the aperiodic BFI report transmitted. The UE may be configured to report the aperiodic BFI report when at least one of the above events is satisfied.

FIG. 10 is a diagram 1000 illustrating an example of a hardware implementation for an apparatus 1002. The apparatus 1002 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatus 1002 may include a cellular baseband processor 1004 (also referred to as a modem) coupled to a cellular RF transceiver 1022. In some aspects, the apparatus 1002 may further include one or more subscriber identity modules (SIM) cards 1020, an application processor 1006 coupled to a secure digital (SD) card 1008 and a screen 1010, a Bluetooth module 1012, a wireless local area network (WLAN) module 1014, a Global Positioning System (GPS) module 1016, or a power supply 1018. The cellular baseband processor 1004 communicates through the cellular RF transceiver 1022 with the UE 104 and/or BS 102/180. The cellular baseband processor 1004 may include a computer-readable medium/memory. The computer-readable medium/memory may be non-transitory. The cellular baseband processor 1004 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the cellular baseband processor 1004, causes the cellular baseband processor 1004 to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the cellular baseband processor 1004 when executing software. The cellular baseband processor 1004 further includes a reception component 1030, a communication manager 1032, and a transmission component 1034. The communication manager 1032 includes the one or more illustrated components. The components within the communication manager 1032 may be stored in the computer-readable medium/memory and/or configured as hardware within the cellular baseband processor 1004. The cellular baseband processor 1004 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359. In one configuration, the apparatus 1002 may be a modem chip and include just the baseband processor 1004, and in another configuration, the apparatus 1002 may be the entire UE (e.g., see 350 of FIG. 3 ) and include the additional modules of the apparatus 1002.

The communication manager 1032 includes a BFD-RS component 1040 that is configured to receive at least one BFD-RS, and measure the BFD-RS received from the base station to detect the radio link quality, e.g., as described in connection with 602, 608, and 702. The communication manager 1032 further includes a BFI report component 1042 that is configured to receive a configuration of the BFI report, receive the instruction to transmit the BFI report, determine the BFI counts based on the measurement of the BFD-RS, and transmit an aperiodic BFI report prior to a beam failure detection, the BFI report being based on at least one measurement of the at least one BFD-RS received from the base station, e.g., as described in connection with 604, 606, 610, 612, and 712.

The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of FIGS. 5, 6, and 7 . As such, each block in the flowcharts of FIGS. 5, 6, and 7 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

As shown, the apparatus 1002 may include a variety of components configured for various functions. In one configuration, the apparatus 1002, and in particular the cellular baseband processor 1004, includes means for receiving, from a base station, at least one BFD-RS, and means for transmitting, to the base station, an aperiodic BFI report prior to a beam failure detection, the BFI report being based on at least one measurement of the at least one BFD-RS received from the base station. The apparatus 1002 includes means for receiving, from the base station, an instruction to transmit the BFI report, and means for receiving, from the base station, a configuration of the BFI report, the BFI report being based on the configuration received from the base station. The means may be one or more of the components of the apparatus 1002 configured to perform the functions recited by the means. As described supra, the apparatus 1002 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the means.

FIG. 11 is a diagram 1100 illustrating an example of a hardware implementation for an apparatus 1102. The apparatus 1102 may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus 1002 may include a baseband unit 1104. The baseband unit 1104 may communicate through a cellular RF transceiver 1122 with the UE 104. The baseband unit 1104 may include a computer-readable medium/memory. The baseband unit 1104 is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the baseband unit 1104, causes the baseband unit 1104 to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the baseband unit 1104 when executing software. The baseband unit 1104 further includes a reception component 1130, a communication manager 1132, and a transmission component 1134. The communication manager 1132 includes the one or more illustrated components. The components within the communication manager 1132 may be stored in the computer-readable medium/memory and/or configured as hardware within the baseband unit 1104. The baseband unit 1104 may be a component of the base station 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

The communication manager 1132 includes a BFD-RS component 1140 that is configured to transmit at least one BFD-RS for measurement, e.g., as described in connection with 802 and 902. The communication manager 1132 further includes a BFI report component 1142 that is configured to transmit a configuration of the BFI report, transmit an instruction to transmit the BFI report, and receive the aperiodic BFI report prior to the beam failure detection, e.g., as described in connection with 804, 806, 808, and 908. The communication manager 1132 further includes an early beam failure component 1144 that is configured to determine whether an early beam failure occurred based on the received BFI report, e.g., as described in connection with 810. The communication manager 1132 further includes a beam failure recovery component 1146 that is configured to initiate a beam failure recovery, e.g., as described in connection with 812.

The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of FIGS. 5, 8, and 9 . As such, each block in the flowcharts of FIGS. 5, 8, and 9 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

As shown, the apparatus 1102 may include a variety of components configured for various functions. In one configuration, the apparatus 1102, and in particular the baseband unit 1104, includes means for transmitting, from a UE, at least one BFD-RS, and means for receiving, from the UE, an aperiodic BFI report prior to a beam failure detection, the BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE. The apparatus 1102 includes means for transmitting, to the UE, an instruction to transmit the BFI report, means for determining whether an early beam failure occurred based on the received BFI report, means for initiating a beam failure recovery. The apparatus 1102 includes means for transmitting, to the UE, a configuration of the BFI report, the BFI report being generated based on the configuration received from the base station. The means may be one or more of the components of the apparatus 1102 configured to perform the functions recited by the means. As described supra, the apparatus 1102 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the means.

The apparatus may include a base station and a UE. The base station may transmit at least one BFD-RS to the UE and the UE may receive at least one BFD-RS from a base station. The UE may determine BFI counts based on the measurement of the BFD-RS, and transmit the aperiodic BFI report to the base station prior to detecting the beam failure. The UE may transmit an aperiodic BFI report to the base station prior to the beam failure detection. The base station may receive the aperiodic BFI report and determine whether an early beam failure occurred based on the received BFI Report. The base station may initiate the beam failure recovery. The aperiodic BFI reporting may provide the early detection of beam failure. Compared to BFR procedure including the RACH procedure, the aperiodic BFI reporting may provide faster beam failure recovery procedures, and have reduced power consumption. The base station may consider a more comprehensive channel condition record from the BFI report to determine the early detection of the beam failure.

It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Terms such as “if,” “when,” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”

The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation.

Aspect 1 is an apparatus for wireless communication at a UE, including at least one processor coupled to a memory and configured to receive, from a base station, at least one BFD-RS, and transmit, to the base station, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the BFD-RS received from the base station.

Aspect 2 is the apparatus of aspect 1, where the aperiodic BFI report includes BFI counts within a period of time, the BFI being reported in response to a comparison of the at least one measurement of the BFD-RS to a threshold value.

Aspect 3 is the apparatus of any of

aspects

1 and 2, where the aperiodic BFI report includes one or more channel condition measurements of the BFD-RS.

Aspect 4 is the apparatus of any of aspects 1 to 3, where the aperiodic BFI report is transmitted with a CSI report.

Aspect 5 is the apparatus of any of aspects 1 to 4, where the aperiodic BFI report is transmitted to the base station in response to a triggering condition based on the BFI counts.

Aspect 6 is the apparatus of aspect 5, where the triggering condition includes at least one of the BFI counts being equal to a threshold BFI value, a first number of BFIs being consecutively reported, or the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS.

Aspect 7 is the apparatus of any of aspects 1 to 6, where the aperiodic BFI report is transmitted via a MAC-CE or UCI.

Aspect 8 is the apparatus of any of aspects 1 to 7, where the at least one processor and the memory are further configured to receive, from the base station, an instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is transmitted to the base station in response to receiving the instruction from the base station.

Aspect 9 is the apparatus of aspect 8, where the instruction to transmit the aperiodic BFI report is received via a MAC-CE or DCI.

Aspect 10 is the apparatus of any of aspects 1 to 9, where the at least one processor and the memory are further configured to receive, from the base station, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station.

Aspect 11 is the apparatus of aspect 10, where the configuration of the aperiodic BFI report is received via at least one of an RRC message configuring a plurality of parameters of the aperiodic BFI report, or a MAC-CE or DCI activating at least one parameter of the aperiodic BFI report among the of parameters of the aperiodic BFI report configured by the RRC message.

Aspect 12 is a method of wireless communication for implementing any of aspects 1 to 11.

Aspect 13 is an apparatus for wireless communication including means for implementing any of aspects 1 to 11.

Aspect 14 is a computer-readable medium storing computer executable code, where the code when executed by a processor causes the processor to implement any of aspects 1 to 11.

Aspect 15 is an apparatus for wireless communication at a base station, including at least one processor coupled to a memory and configured to transmit, from a UE, at least one BFD-RS, and receive, from the UE, an aperiodic BFI report prior to a beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the BFD-RS transmitted to the UE.

Aspect 16 is the apparatus of aspect 15, where the aperiodic BFI report includes BFI counts within a period of time at the UE, the BFI being reported in response to an error rate measurement of the BFD-RS being greater than a threshold value.

Aspect 17 is the apparatus of any of aspects 15 and 16, where the aperiodic BFI report includes one or more channel condition measurements of the BFD-RS.

Aspect 18 is the apparatus of any of aspects 15 to 17, where the aperiodic BFI report is transmitted with a CSI report.

Aspect 19 is the apparatus of any of aspects 15 to 18, where the aperiodic BFI report is transmitted via a MAC-CE or UCI.

Aspect 20 is the apparatus of any of aspects 15 to 19, where the at least one processor and the memory are further configured to transmit, to the UE, an instruction to transmit the aperiodic BFI report, where the aperiodic BFI report is received from the UE in response to transmitting the instruction from to the UE.

Aspect 21 is the apparatus of aspect 20, where the instruction to transmit the aperiodic BFI report is received via a MAC-CE or DCI.

Aspect 22 is the apparatus of any of aspects 15 to 21, where the instruction triggering the aperiodic BFI report is transmitted based on an occurrence of a condition at the base station.

Aspect 23 is the apparatus of any of aspects 15 to 22, where the at least one processor and the memory are further configured to determine whether an early beam failure occurred based on the received aperiodic BFI report.

Aspect 24 is the apparatus of aspect 23, where the aperiodic BFI report includes at least one channel condition measurement associated with the UE, the early beam failure is determined based on the at least one of at least one BFI count at the UE being equal to a threshold BFI value, a first number of BFIs being consecutively reported at the UE, the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE, or the at least one channel condition measurement associated with the UE.

Aspect 25 is the apparatus of any of aspects 15 to 24, where the at least one processor and the memory are further configured to initiate a beam failure recovery, the beam failure recovery including at least one of initiating a beam switch of the UE, silencing other UEs neighboring the UE, initiate conditional hand over to a nearby base station.

Aspect 26 is the apparatus of any of aspects 15 to 25, where the at least one processor and the memory are further configured to transmit, to the UE, a configuration of the aperiodic BFI report, the aperiodic BFI report being generated based on the configuration received from the base station.

Aspect 27 is a method of wireless communication for implementing any of aspects 15 to 26.

Aspect 28 is an apparatus for wireless communication including means for implementing any of aspects 15 to 26.

Aspect 29 is a computer-readable medium storing computer executable code, where the code when executed by a processor causes the processor to implement any of aspects 15 to 26.

Claims

What is claimed is:

1. An apparatus for wireless communication at a user equipment (UE), comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor and the memory configured to:

receive, from a base station, at least one beam failure detection (BFD) reference signal (RS) (BFD-RS); and

transmit, to the base station, an aperiodic beam failure indication (BFI) report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station.

2. The apparatus of claim 1, wherein the aperiodic BFI report includes BFI counts within a period of time, the BFI being reported in response to a comparison of the at least one measurement of the BFD-RS to a threshold value.

3. The apparatus of claim 1, wherein the aperiodic BFI report includes one or more channel condition measurements of the BFD-RS.

4. The apparatus of claim 1, wherein the aperiodic BFI report is transmitted with a channel state information (CSI) report.

5. The apparatus of claim 2, wherein the aperiodic BFI report is transmitted to the base station in response to a triggering condition based on the BFI counts.

6. The apparatus of claim 5, wherein the triggering condition includes at least one of the BFI counts being equal to a threshold BFI value, a first number of BFIs being consecutively reported, or the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS.

7. The apparatus of claim 1, wherein the aperiodic BFI report is transmitted via a medium access control (MAC) control element (CE) (MAC-CE) or uplink control information (UCI).

8. The apparatus of claim 1, wherein the at least one processor and the memory are further configured to receive, from the base station, an instruction to transmit the aperiodic BFI report, wherein the aperiodic BFI report is transmitted to the base station in response to receiving the instruction from the base station.

9. The apparatus of claim 8, wherein the instruction to transmit the aperiodic BFI report is received via a medium access control (MAC) control element (CE) (MAC-CE) or downlink control information (DCI).

10. The apparatus of claim 1, wherein the at least one processor and the memory are further configured to receive, from the base station, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station.

11. The apparatus of claim 10, wherein the configuration of the aperiodic BFI report is received via at least one of:

a radio resource control (RRC) message configuring a plurality of parameters of the aperiodic BFI report, or

a medium access control (MAC) control element (CE) (MAC-CE) or downlink control information (DCI) activating at least one parameter of the aperiodic BFI report among the of parameters of the aperiodic BFI report configured by the RRC message.

12. A method of wireless communication at a user equipment (UE), comprising:

receiving, from a base station, at least one beam failure detection (BFD) reference signal (RS) (BFD-RS); and

transmitting, to the base station, an aperiodic beam failure indication (BFI) report prior to a beam failure detection, the aperiodic BFI report being based on at least one measurement of the at least one BFD-RS received from the base station.

13. The method of claim 12, further comprising receiving, from the base station, an instruction to transmit the aperiodic BFI report, wherein the aperiodic BFI report is transmitted to the base station in response to receiving the instruction from the base station.

14. The method of claim 12, further comprising receiving, from the base station, a configuration of the aperiodic BFI report, the aperiodic BFI report being based on the configuration received from the base station.

15. An apparatus for wireless communication at a base station, comprising:

a memory; and

transmit, to a user equipment (UE), at least one beam failure detection (BFD) reference signal (RS) (BFD-RS); and

receive, from the UE, an aperiodic beam failure indication (BFI) report prior to a beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE.

16. The apparatus of claim 15, wherein the aperiodic BFI report includes BFI counts within a period of time at the UE, the BFI being reported in response to an error rate measurement of the BFD-RS being greater than a threshold value.

17. The apparatus of claim 15, wherein the aperiodic BFI report includes one or more channel condition measurements of the BFD-RS.

18. The apparatus of claim 15, wherein the aperiodic BFI report is received with a channel state information (C SI) report.

19. The apparatus of claim 15, wherein the aperiodic BFI report is received via a medium access control (MAC) control element (CE) (MAC-CE) or uplink control information (UCI).

20. The apparatus of claim 15, wherein the at least one processor and the memory are further configured to transmit, to the UE, an instruction to transmit the aperiodic BFI report,

wherein the aperiodic BFI report is received from the UE in response to transmitting the instruction from to the UE.

21. The apparatus of claim 20, wherein the instruction to transmit the aperiodic BFI report is received via a medium access control (MAC) control element (CE) (MAC-CE) or downlink control information (DCI).

22. The apparatus of claim 20, wherein the instruction triggering the aperiodic BFI report is transmitted based on an occurrence of a condition at the base station.

23. The apparatus of claim 15, wherein the at least one processor and the memory are further configured to determine whether an early beam failure occurred based on the received aperiodic BFI report.

24. The apparatus of claim 23, wherein the aperiodic BFI report includes at least one channel condition measurement associated with the UE, the early beam failure is determined based on the at least one of:

at least one BFI count at the UE being equal to a threshold BFI value;

a first number of BFIs being consecutively reported at the UE;

the measurement of one BFD-RS dropping more than a first dB from a measurement of previously received BFD-RS at the UE; or

the at least one channel condition measurement associated with the UE.

25. The apparatus of claim 15, wherein the at least one processor and the memory are further configured to initiate a beam failure recovery, the beam failure recovery including at least one of initiating a beam switch of the UE, silencing other UEs neighboring the UE, initiate conditional hand over to a nearby base station.

26. The apparatus of claim 15, wherein the at least one processor and the memory are further configured to transmit, to the UE, a configuration of the aperiodic BFI report, the aperiodic BFI report being generated based on the configuration received from the base station.

27. The apparatus of claim 25, wherein the configuration of the aperiodic BFI report includes at least one of:

28. A method of wireless communication at a base station, comprising:

transmitting, to a user equipment (UE), at least one beam failure detection (BFD) reference signal (RS) (BFD-RS); and

receiving, from the UE, an aperiodic beam failure indication (BFI) report prior to a beam failure detection, the aperiodic BFI report being generated based on at least one measurement of the at least one BFD-RS transmitted to the UE.

29. The method of claim 28, further comprising determining whether an early beam failure occurred based on the received aperiodic BFI report.

30. The method of claim 28, further comprising initiating a beam failure recovery, the beam failure recovery including at least one of initiating a beam switch of the UE, silencing other UEs neighboring the UE, initiate conditional hand over to a nearby base station.